Docker中文教程

HECD架构

容器创建步骤：

1.从etcd读取docker的host信息，包括appname与ip。

2.由confd生成haproxy配置文件，读取etcd的变量信息。

3.最后由Python API操作创建docker容器。

介绍

Etcd是一个高可用的 Key/Value 存储系统，主要用于分享配置和服务发现。 简单：支持 curl 方式的用户 API 。

Confd介绍

Confd是一个轻量级的配置管理工具。通过查询Etcd，结合配置模板引擎，保持本地配置最新，同时具备定期探测机制，配置变更自动reload。

安装

宿主机安装

yum -y install docker-io

etcd安装

wget https://github.com/coreos/etcd/releases/download/v0.4.6/etcd-v0.4.6-linux-amd64.tar.gz
tar -zxvf etcd-v0.4.6-linux-amd64.tar.gz
cd etcd-v0.4.6-linux-amd64
cp etcd* /bin/

confd与haproxy

yum -y install haproxy

wget https://github.com/kelseyhightower/confd/releases/download/v0.6.3/confd-0.6.3-linux-amd64
mv confd /usr/local/bin/confd
chmod +x /usr/local/bin/confd

etcd部分

启动

#-peer-addr：与其他节点通讯socket
#-addr：服务监听socket
#-data-dir：存储目录
/bin/etcd -name etcdserver -peer-addr 192.168.1.21:7001 -addr 192.168.1.21:4001 -data-dir /data/etcd -peer-bind-addr 0.0.0.0:7001 -bind-addr 0.0.0.0:4001 &

实例

#设置key
curl -L http://192.168.1.21:4001/v2/keys/testkey -XPUT -d value="this is testkey"
#获取key
curl -L http://192.168.1.21:4001/v2/keys/testkey  
#删除key
curl -L http://192.168.1.21:4001/v2/keys/testkey -XDELETE

confd + haproxy部分

/etc/confd/conf.d/ haproxy.toml

[template]
src = "haproxy.cfg.tmpl"
dest = "/etc/haproxy/haproxy.cfg"
keys = [
  "/app/servers",
]
reload_cmd = "/etc/init.d/haproxy reload"

/etc/confd/templates/haproxy.cfg.tmpl

global
        log 127.0.0.1 local3
        maxconn 5000
        uid 99
        gid 99
        daemon

defaults
        log 127.0.0.1 local3
        mode http
        option dontlognull
        retries 3
        option redispatch
        maxconn 2000
        contimeout  5000
        clitimeout  50000
        srvtimeout  50000

listen frontend 0.0.0.0:80
        mode http
        balance roundrobin
        maxconn 2000
        option forwardfor
        {{range gets "/app/servers/*"}}
        server {{base .Key}} {{.Value}} check inter 5000 fall 1 rise 2
        {{end}}

        stats enable
        stats uri /admin-status
        stats auth admin:123456
        stats admin if TRUE

语法见http://golang.org/pkg/text/template/

启动

#interval探测频率，node监控socket，confdir配置目录
/usr/local/bin/confd -verbose -interval 10 -node '192.168.1.21:4001' -confdir /etc/confd > /var/log/confd.log &

docker启动程序实例（by 刘天斯）

import docker
import etcd
import sys

Etcd_ip="192.168.1.21"
Server_ip="192.168.1.22"
App_port="80"
App_protocol="tcp"
Image="yorko/webserver:v3"

Port=""
Name=""

idict={}
rinfo={}
try:
    c = docker.Client(base_url='tcp://'+Server_ip+':2375',version='1.14',timeout=15)
except Exception,e:
    print "Connection docker server error:"+str(e)
    sys.exit()

try:
    rinfo=c.create_container(image=Image,stdin_open=True,tty=True,command="/usr/bin/supervisord -c /etc/supervisord.conf",volumes=['/data','/etc/httpd/conf','/etc/httpd/conf.d
','/etc/localtime'],ports=[80,22],name=None)
    containerId=rinfo['Id']
except Exception,e:
    print "Create docker container error:"+str(e)
    sys.exit()

try:
    c.start(container=containerId, binds={'/data':{'bind': '/data','ro': False},'/etc/httpd/conf':{'bind': '/etc/httpd/conf','ro': True},'/etc/httpd/conf.d':{'bind': '/etc/htt
pd/conf.d','ro': True},'/etc/localtime':{'bind': '/etc/localtime','ro': True}}, port_bindings={80:None,22:None}, lxc_conf=None,publish_all_ports=True, links=None, privileged=F
alse,dns='172.17.42.1', dns_search=None, volumes_from=None, network_mode=None,restart_policy=None, cap_add=None, cap_drop=None)
except Exception,e:
    print "Start docker container error:"+str(e)
    sys.exit()

try:
    idict=c.inspect_container(containerId)
    Name=idict["Name"][1:]
    skey=App_port+'/'+App_protocol
    for _key in idict["NetworkSettings"]["Ports"].keys():
        if _key==skey:
            Port=idict["NetworkSettings"]["Ports"][skey][0]["HostPort"]
except Exception,e:
    print "Get docker container inspect error:"+str(e)
    sys.exit()

if Name!="" and Port!="":
    try:
        client = etcd.Client(host=Etcd_ip, port=4001)
        client.write('/app/servers/'+Name, Server_ip+":"+str(Port))
        print Name+" container run success!"
    except Exception,e:
    print "set etcd key error:"+str(e)
else:
    print "Get container name or port error."